Not applicable.
Not applicable.
1. Field of the Invention
The present invention generally relates to network interface controllers (NICs) for coupling a computer system to a local area network (LAN). More particularly, the invention relates to a management system that monitors the performance and failure of an associated computer or server. Still more particularly, the present invention relates to a management system that shares an Ethernet NIC with the computer system it manages.
2. Background of the Invention
Distributed computer networks such as LAN""s (local area networks) have become one of the most important devices for storing and sharing data in a business, and thus, computer networks are one of the most critical pieces of equipment in a business office. Computer networks typically comprise a plurality of personal computers and other data processing devices connected together for information exchange. At the heart of the computer network is one or more file servers. In most computer networks, file servers are responsible for administrating and storing the documents generated by each of the personal computers (PC""s) in the system. Needless to say, a failure in the computer network can cause business operations to grind to a halt. In addition to managing the network, file servers also preferably include the capability to monitor faults in the computer network. If a fault or security breach is detected, the file server provides a warning of the fault and in certain instances may also provide diagnostic operations and may even implement corrective measures.
Servers typically connect to the network through a network interface controller (NIC). The NIC typically connects to a system bus (such as the PCI bus or EISA bus) within the server. The NIC also usually couples, via a suitable cable, to the network (such as an Ethernet bus), which is a set of wires that link together all of the computers, printers and all other peripheral resources available via the network. If a server""s NIC fails, access to the server is no longer available, and the server is no longer capable of transmitting data or instructions to the network.
Because of the relative importance of servers to a business, there has been a trend recently to provide a management sub-system with servers. These management sub-systems may be provided as part of the server itself, may be inserted as expansion cards in the server expansion bay, or may comprise a separate xe2x80x9cstand-alonexe2x80x9d unit that connects electrically to the server. Regardless of how implemented, the management sub-systems typically are designed to monitor the operation of certain aspects of the server, and if necessary, to repair or reboot the server in the event of failure. Many management sub-systems contact a systems administrator if an error is detected that cannot be repaired. Some management sub-systems may even take over certain critical operations of the server until it has been repaired.
If implemented as part of a xe2x80x9cdedicatedxe2x80x9d management network, the management sub-system usually includes a separate network interface controller (NIC). This NIC couples the management system to a management console, either via the network, or through a modem connection on the network. Oftentimes, the management sub-system is linked to the management console via a secure connection that is limited for use by the system administrator for administration and management operations. Thus, typically, both the management sub-system and the server are on separate networks and have separate network interface controllers, with different MAC addresses.
It would be advantageous if the server system and management sub-system could share a NIC for certain functions. In particular, it would be desirable to use a NIC to interface both the management sub-system and the server to the management console to provide the system administrator with a secure connection to both the management sub-system and the server. Thus, in addition to communicating with the management sub-system via the management NIC, other management operations involving the server also could be performed using the management NIC. These operations include, but are not limited to, server health agents, file sharing and application performance reporting. Such a system would permit management functions on the network to be isolated from normal data storage and retrieval functions. Alternatively, if the server NIC and management sub system NIC are located on the same network, it would be desirable if the management sub-system NIC could also function as a back-up NIC for the server in the event that the server NIC fails.
The problems noted above are solved in large part by a system that includes a management sub-system that is associated with a host server computer system such as a server, for managing and monitoring the host system. Both the host system and the management sub-system include a network interface controller (NIC) capable of interfacing with the network, which may comprise a Local Area Network (LAN) implemented with an Ethernet link. In the preferred embodiment, the host computer also couples through the management NIC, to permit all management operations to be consolidated through a common, secure network interface controller. In addition, the system may be configured so that the host system can use the management NIC in the event that the host NIC fails.
In the preferred embodiment, the system management sub-system couples to a system bus of the host computer system. The management sub-system includes a management processor and associated software, including management software and a management NIC. The management NIC includes modified packet decode logic that accepts addresses to both the management sub-system and to the host computer system. If the destination address of the packet targets the management sub-system, the packet data is routed to the management processor by a software multiplexer/demultiplexer. If, conversely, the destination address targets the server, the data is routed to the server by the multiplexer/demultiplexer.
According to the preferred embodiment, all management operations relating to the host system are routed through the management NIC. Other normal data transactions to the host system are routed through that system""s NIC, thus isolating management operations from standard data operations. In the event the host NIC fails, all outgoing data packets from the host system may be re-routed by the host processor through the management NIC if the host NIC and management NIC are on the same network. Moreover, the management NIC may be used in situations where the host NIC becomes overly busy and is unable to process pending network transactions to and from the host computer.